Allocate static boxes on FOH (#79188)

Co-authored-by: Jan Kotas <jkotas@microsoft.com>

Author: EgorBo

src/coreclr/inc/CrstTypes.def

@@ -577,3 +577,7 @@ End
 Crst PgoData
     AcquiredBefore LoaderHeap
 End
+
+Crst StaticBoxInit
+    AcquiredBefore LoaderHeap FrozenObjectHeap AssemblyLoader
+End

src/coreclr/inc/crsttypes_generated.h

@@ -112,28 +112,29 @@ enum CrstType
     CrstSingleUseLock = 94,
     CrstSpecialStatics = 95,
     CrstStackSampler = 96,
-    CrstStressLog = 97,
-    CrstStubCache = 98,
-    CrstStubDispatchCache = 99,
-    CrstStubUnwindInfoHeapSegments = 100,
-    CrstSyncBlockCache = 101,
-    CrstSyncHashLock = 102,
-    CrstSystemBaseDomain = 103,
-    CrstSystemDomain = 104,
-    CrstSystemDomainDelayedUnloadList = 105,
-    CrstThreadIdDispenser = 106,
-    CrstThreadStore = 107,
-    CrstTieredCompilation = 108,
-    CrstTypeEquivalenceMap = 109,
-    CrstTypeIDMap = 110,
-    CrstUMEntryThunkCache = 111,
-    CrstUMEntryThunkFreeListLock = 112,
-    CrstUniqueStack = 113,
-    CrstUnresolvedClassLock = 114,
-    CrstUnwindInfoTableLock = 115,
-    CrstVSDIndirectionCellLock = 116,
-    CrstWrapperTemplate = 117,
-    kNumberOfCrstTypes = 118
+    CrstStaticBoxInit = 97,
+    CrstStressLog = 98,
+    CrstStubCache = 99,
+    CrstStubDispatchCache = 100,
+    CrstStubUnwindInfoHeapSegments = 101,
+    CrstSyncBlockCache = 102,
+    CrstSyncHashLock = 103,
+    CrstSystemBaseDomain = 104,
+    CrstSystemDomain = 105,
+    CrstSystemDomainDelayedUnloadList = 106,
+    CrstThreadIdDispenser = 107,
+    CrstThreadStore = 108,
+    CrstTieredCompilation = 109,
+    CrstTypeEquivalenceMap = 110,
+    CrstTypeIDMap = 111,
+    CrstUMEntryThunkCache = 112,
+    CrstUMEntryThunkFreeListLock = 113,
+    CrstUniqueStack = 114,
+    CrstUnresolvedClassLock = 115,
+    CrstUnwindInfoTableLock = 116,
+    CrstVSDIndirectionCellLock = 117,
+    CrstWrapperTemplate = 118,
+    kNumberOfCrstTypes = 119
 };
 
 #endif // __CRST_TYPES_INCLUDED
@@ -241,6 +242,7 @@ int g_rgCrstLevelMap[] =
     5,          // CrstSingleUseLock
     0,          // CrstSpecialStatics
     0,          // CrstStackSampler
+    13,         // CrstStaticBoxInit
     -1,         // CrstStressLog
     5,          // CrstStubCache
     0,          // CrstStubDispatchCache
@@ -364,6 +366,7 @@ LPCSTR g_rgCrstNameMap[] =
     "CrstSingleUseLock",
     "CrstSpecialStatics",
     "CrstStackSampler",
+    "CrstStaticBoxInit",
     "CrstStressLog",
     "CrstStubCache",
     "CrstStubDispatchCache",

src/coreclr/vm/appdomain.cpp

@@ -637,6 +637,7 @@ void BaseDomain::Init()
     m_NativeTypeLoadLock.Init(CrstInteropData, CrstFlags(CRST_REENTRANCY), TRUE);
 
     m_crstLoaderAllocatorReferences.Init(CrstLoaderAllocatorReferences);
+    m_crstStaticBoxInitLock.Init(CrstStaticBoxInit);
     // Has to switch thread to GC_NOTRIGGER while being held (see code:BaseDomain#AssemblyListLock)
     m_crstAssemblyList.Init(CrstAssemblyList, CrstFlags(
         CRST_GC_NOTRIGGER_WHEN_TAKEN | CRST_DEBUGGER_THREAD | CRST_TAKEN_DURING_SHUTDOWN));

src/coreclr/vm/appdomain.hpp

@@ -1088,6 +1088,12 @@ class BaseDomain
         return &m_crstLoaderAllocatorReferences;
     }
 
+    CrstExplicitInit* GetStaticBoxInitLock()
+    {
+        LIMITED_METHOD_CONTRACT;
+        return &m_crstStaticBoxInitLock;
+    }
+
     static CrstStatic* GetMethodTableExposedClassObjectLock()
     {
         LIMITED_METHOD_CONTRACT;
@@ -1112,6 +1118,7 @@ class BaseDomain
     CrstExplicitInit m_DomainLocalBlockCrst;
     // Used to protect the reference lists in the collectible loader allocators attached to this appdomain
     CrstExplicitInit m_crstLoaderAllocatorReferences;
+    CrstExplicitInit m_crstStaticBoxInitLock;
 
     //#AssemblyListLock
     // Used to protect the assembly list. Taken also by GC or debugger thread, therefore we have to avoid

src/coreclr/vm/frozenobjectheap.cpp

@@ -37,6 +37,10 @@ Object* FrozenObjectHeapManager::TryAllocateObject(PTR_MethodTable type, size_t
     _ASSERT(type != nullptr);
     _ASSERT(FOH_COMMIT_SIZE >= MIN_OBJECT_SIZE);
 
+#ifdef FEATURE_64BIT_ALIGNMENT
+    _ASSERT(!type->RequiresAlign8());
+#endif
+
     // NOTE: objectSize is expected be the full size including header
     _ASSERT(objectSize >= MIN_OBJECT_SIZE);
 

src/coreclr/vm/jitinterface.cpp

@@ -1560,8 +1560,32 @@ void CEEInfo::getFieldInfo (CORINFO_RESOLVED_TOKEN * pResolvedToken,
 
                 GCX_COOP();
 
+                _ASSERT(!pFieldMT->Collectible());
+                // Field address is expected to be pinned so we don't need to protect it from GC here
                 pResult->fieldLookup.addr = pField->GetStaticAddressHandle((void*)pField->GetBase());
                 pResult->fieldLookup.accessType = IAT_VALUE;
+                if (fieldFlags & CORINFO_FLG_FIELD_STATIC_IN_HEAP)
+                {
+                    Object* frozenObj = VolatileLoad((Object**)pResult->fieldLookup.addr);
+
+                    if (frozenObj == nullptr)
+                    {
+                        // Boxed static is not yet set, allocate it
+                        pFieldMT->AllocateRegularStaticBox(pField, (Object**)pResult->fieldLookup.addr);
+                        frozenObj = VolatileLoad((Object**)pResult->fieldLookup.addr);
+                    }
+
+                    _ASSERT(frozenObj != nullptr);
+
+                    // ContainsPointers here is unnecessary but it's cheaper than IsInFrozenSegment
+                    // for structs containing gc handles
+                    if (!frozenObj->GetMethodTable()->ContainsPointers() &&
+                        GCHeapUtilities::GetGCHeap()->IsInFrozenSegment(frozenObj))
+                    {
+                        pResult->fieldLookup.addr = frozenObj->GetData();
+                        fieldFlags &= ~CORINFO_FLG_FIELD_STATIC_IN_HEAP;
+                    }
+                }
             }
         }
 

src/coreclr/vm/methodtable.cpp

@@ -58,6 +58,7 @@
 #include "array.h"
 #include "castcache.h"
 #include "dynamicinterfacecastable.h"
+#include "frozenobjectheap.h"
 
 #ifdef FEATURE_INTERPRETER
 #include "interpreter.h"
@@ -3495,13 +3496,7 @@ void MethodTable::AllocateRegularStaticBoxes()
 
             if (!pField->IsSpecialStatic() && pField->IsByValue())
             {
-                TypeHandle  th = pField->GetFieldTypeHandleThrowing();
-                MethodTable* pFieldMT = th.GetMethodTable();
-
-                LOG((LF_CLASSLOADER, LL_INFO10000, "\tInstantiating static of type %s\n", pFieldMT->GetDebugClassName()));
-                OBJECTREF obj = AllocateStaticBox(pFieldMT, HasFixedAddressVTStatics());
-
-                SetObjectReference( (OBJECTREF*)(pStaticBase + pField->GetOffset()), obj);
+                AllocateRegularStaticBox(pField, (Object**)(pStaticBase + pField->GetOffset()));
             }
 
             pField++;
@@ -3510,14 +3505,47 @@ void MethodTable::AllocateRegularStaticBoxes()
     GCPROTECT_END();
 }
 
+void MethodTable::AllocateRegularStaticBox(FieldDesc* pField, Object** boxedStaticHandle)
+{
+    CONTRACTL
+    {
+        THROWS;
+        GC_TRIGGERS;
+        MODE_COOPERATIVE;
+        CONTRACTL_END;
+    }
+    _ASSERT(pField->IsStatic() && !pField->IsSpecialStatic() && pField->IsByValue());
+
+    // Static fields are not pinned in collectible types so we need to protect the address
+    GCPROTECT_BEGININTERIOR(boxedStaticHandle);
+    if (VolatileLoad(boxedStaticHandle) == nullptr)
+    {
+        // Grab field's type handle before we enter lock
+        MethodTable* pFieldMT = pField->GetFieldTypeHandleThrowing().GetMethodTable();
+        bool hasFixedAddr = HasFixedAddressVTStatics();
+
+        // Taking a lock since we might come here from multiple threads/places
+        CrstHolder crst(GetAppDomain()->GetStaticBoxInitLock());
+
+        // double-checked locking
+        if (VolatileLoad(boxedStaticHandle) == nullptr)
+        {
+            LOG((LF_CLASSLOADER, LL_INFO10000, "\tInstantiating static of type %s\n", pFieldMT->GetDebugClassName()));
+            OBJECTREF obj = AllocateStaticBox(pFieldMT, hasFixedAddr, NULL, false);
+            SetObjectReference((OBJECTREF*)(boxedStaticHandle), obj);
+        }
+    }
+    GCPROTECT_END();
+}
+
 //==========================================================================================
-OBJECTREF MethodTable::AllocateStaticBox(MethodTable* pFieldMT, BOOL fPinned, OBJECTHANDLE* pHandle)
+OBJECTREF MethodTable::AllocateStaticBox(MethodTable* pFieldMT, BOOL fPinned, OBJECTHANDLE* pHandle, bool canBeFrozen)
 {
     CONTRACTL
     {
         THROWS;
         GC_TRIGGERS;
-        MODE_ANY;
+        MODE_COOPERATIVE;
         CONTRACTL_END;
     }
 
@@ -3526,7 +3554,22 @@ OBJECTREF MethodTable::AllocateStaticBox(MethodTable* pFieldMT, BOOL fPinned, OB
     // Activate any dependent modules if necessary
     pFieldMT->EnsureInstanceActive();
 
-    OBJECTREF obj = AllocateObject(pFieldMT);
+    OBJECTREF obj = NULL;
+    if (canBeFrozen)
+    {
+        // In case if we don't plan to collect this handle we may try to allocate it on FOH
+        _ASSERT(!pFieldMT->ContainsPointers());
+        _ASSERT(pHandle == nullptr);
+        FrozenObjectHeapManager* foh = SystemDomain::GetFrozenObjectHeapManager();
+        obj = ObjectToOBJECTREF(foh->TryAllocateObject(pFieldMT, pFieldMT->GetBaseSize()));
+        // obj can be null in case if struct is huge (>64kb)
+        if (obj != NULL)
+        {
+            return obj;
+        }
+    }
+
+    obj = AllocateObject(pFieldMT);
 
     // Pin the object if necessary
     if (fPinned)

src/coreclr/vm/methodtable.h

@@ -831,7 +831,8 @@ class MethodTable
     // instantiations of the superclass or interfaces e.g. System.Int32 : IComparable<System.Int32>
 
     void AllocateRegularStaticBoxes();
-    static OBJECTREF AllocateStaticBox(MethodTable* pFieldMT, BOOL fPinned, OBJECTHANDLE* pHandle = 0);
+    void AllocateRegularStaticBox(FieldDesc* pField, Object** boxedStaticHandle);
+    static OBJECTREF AllocateStaticBox(MethodTable* pFieldMT, BOOL fPinned, OBJECTHANDLE* pHandle = 0, bool canBeFrozen = false);
 
     void CheckRestore();
 

src/tests/baseservices/compilerservices/FixedAddressValueType/FixedAddressValueType.cs

@@ -1,59 +1,50 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 //
+
 using System;
 using System.Runtime.CompilerServices;
 
-public struct Age {
-   public int years;
-   public int months;
-}
-
-public class FreeClass
+public struct Age
 {
-   public static Age FreeAge;
-
-   public static unsafe IntPtr AddressOfFreeAge()
-   { 
-      fixed (Age* pointer = &FreeAge) 
-      { return (IntPtr) pointer; } 
-   }
+    public int years;
+    public int months;
 }
 
 public class FixedClass
 {
-   [FixedAddressValueType]
-   public static Age FixedAge;
-
-   public static unsafe IntPtr AddressOfFixedAge()
-   { 
-      fixed (Age* pointer = &FixedAge) 
-      { return (IntPtr) pointer; } 
-   }   
+    [FixedAddressValueType]
+    public static Age FixedAge;
+
+    public static unsafe IntPtr AddressOfFixedAge()
+    {
+        fixed (Age* pointer = &FixedAge)
+        {
+            return (IntPtr)pointer;
+        }
+    }
 }
 
 public class Example
 {
-   public static int Main()
-   {
-      // Get addresses of static Age fields.
-      IntPtr freePtr1 = FreeClass.AddressOfFreeAge();
-
-      IntPtr fixedPtr1 = FixedClass.AddressOfFixedAge();
-
-      // Garbage collection.
-      GC.Collect(3, GCCollectionMode.Forced, true, true);
-      GC.WaitForPendingFinalizers();
-      
-      // Get addresses of static Age fields after garbage collection.
-      IntPtr freePtr2 = FreeClass.AddressOfFreeAge();
-      IntPtr fixedPtr2 = FixedClass.AddressOfFixedAge();
-
-      if(freePtr1 != freePtr2 && fixedPtr1 == fixedPtr2)
-      {
-          return 100;
-      }
-
-      return -1;
-   }
+    public static int Main()
+    {
+        for (int i = 0; i < 1000; i++)
+        {
+            IntPtr fixedPtr1 = FixedClass.AddressOfFixedAge();
+
+            // Garbage collection.
+            GC.Collect(3, GCCollectionMode.Forced, true, true);
+            GC.WaitForPendingFinalizers();
+
+            // Get addresses of static Age fields after garbage collection.
+            IntPtr fixedPtr2 = FixedClass.AddressOfFixedAge();
+
+            if (fixedPtr1 != fixedPtr2)
+            {
+                return -1;
+            }
+        }
+        return 100;
+    }
 }